After decades of anti-seasonal water fluctuation in the Three Gorges Reservoir (TGR), a distinctive riparian zone had been formed and played critical roles on soil biogeochemistry cycling, substance exchange and soil microbial functions. However, the effect of land use on terrestrial ecological processes and soil microbial community assembly in riparian zone was still imprecise. This study focused on the relationship of soil properties and microbial communities in paddy and dryland soils of a typical riparian zone in the TGR. The results indicated a higher level of accumulation of total organic carbon (TOC) in paddy soil (14.88–20.29 g kg⁻¹) than that in dryland soil (7.59–16.20 g kg⁻¹). The riparian soil was slightly polluted by cadmium and phthalate acid esters with an average concentration of 0.19 mg kg⁻¹ and 6.45 mg kg⁻¹, which may be from agricultural sources, posing a potential health risk. Based on 16S rRNA sequencing analysis, there was a higher microbial diversity in paddy soils than dryland soils, and Acidobacteriaceae and Anaerolineaceae represented the dominant taxa in dryland and paddy soils, respectively. Furthermore, the results of redundancy analysis and structural equation modeling showed that land use driven change in soil organic carbon affected the fate of soil pollutants, and constructed soil microbial communities in the riparian zone of TGR. Null model revealed that homogeneous selection explained about 76.36% and 53.33% microbial community assembly, followed by dispersal limitation (14.54% and 37.50%) in dryland and paddy soil. In consequence, a strong effect of environmental filtering was observed on arable soil microbial community structure with different land use in the riparian zone of TGR, and TOC was the key regulator.

三峡水库（TGR）经过数十年的反季节水量波动，形成了独特的河岸带，对土壤生物地球化学循环、物质交换和土壤微生物功能发挥了关键作用。然而，土地利用对河岸带陆地生态过程和土壤微生物群落组装的影响仍然不精确。本研究重点研究了三峡地区典型河岸带稻田和旱地土壤中土壤性质与微生物群落的关系。^{结果表明，稻田土壤（14.88-20.29 g kg -1} ）的总有机碳（TOC）积累水平高于旱地土壤（7.59-16.20 g kg ^{-1 ）}）。河岸土壤受镉和邻苯二甲酸酯轻微污染，平均浓度为0.19 mg kg ^-1和6.45 mg kg ^-1，可能来自农业，存在潜在的健康风险。基于 16S rRNA 测序分析，水稻土中的微生物多样性高于旱地土壤，酸杆菌科和厌氧菌科分别代表旱地和稻田土壤中的主要分类群。此外，冗余分析和结构方程模型的结果表明，土地利用驱动的土壤有机碳变化影响了土壤污染物的去向，并在三峡库河岸区构建了土壤微生物群落。零模型显示，均质选择解释了约 76.36% 和 53.33% 的微生物群落组装，其次是旱地和稻田土壤中的扩散限制（14.54% 和 37.50%）。结果表明，环境过滤对三峡库区不同土地利用方式的耕地土壤微生物群落结构具有较强的影响，其中TOC是关键调节因子。